Electromagnetic pulley



June 8, 1954 D. E. KOERNER ELECTROMAGNETIC PULLEY Filed April 3, 1953 I INVENTOR.

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Patented June 8, 1954 i A l V UNITED STATES PATENT OFFICE 2,680,517 ELECTROMAGNETIC PULLEY Dan E. Koerner, East Troy, Wis., assignor to Dings Magnetic Separator 00., Milwaukee, Wis., a corporation of Wisconsin Application April 3, 1953, Serial No. 346,617

3 Claims. (Cl. 209-419) The present invention relates generally to imeffective range near the center of the advancing provements in the art of magnetically separating stream. With the prior electromagnetic separemoving magnetic substances from non-magmass could not me assui ed due to the substantial netlc bulk material which 1s oidinarily subJected unlioimity or even weaker field at the center to magnetic influence at the pulley or drum peof the pulley face, and the neutralization of some riphery. flux 111168 remote from the pulley periphery The primary object of my invention is to pro- It 1s theiefore an important ob ect of the presmaximum efiiciency in separation of mixed magk netic field is of maximum intensity and most eifecnetic and non-magnetic materials applied to the tive range at the medial portion of the pulley pepulley or drum periphery results. riphery so that the thickest portion of the mass It is common practice to utilize a so-called of material being transported over the pulley purpose of removing magnetic substances from m moval of magnetic substances throughout its entire extent.

Another important object of this invention is riphery of the revolving pulley or drum. In some to provide a magnetic pulley composed of several bulg mixtuie of non-magnetic mater ml and magnon-magnetic material passing through the magnetic substances IS usual y conveyed over the netic fiel pulley periphery by means of a non-magnetic A further important object of the invention is three of which each consisted of the positive pole 4 is to provide an improved electromagnetic sepa- Iace where the strongest field IS in fact desired. teual sub ected to the magnetic field created The belts for conducting the mixed bulk mate- 45 along the pulley periphery rial toward these magnetic separating pulleys are These and other more specific objects and adnecessarily more heavily loaded at the center and vantages of the present invention will be apare frequently troughed in order to prevent spillparent from the following description, from age of mateiial from the opposite sides thereof which it W111 be apparent that the gist of the 1mabout the pulley axis and are energized so as to create a magnetic field extending along the pulley periphery and having maximum intensity at the central plane perpendicular to said axis.

A clear conception of the features constituting the present improvement, and of the construction and operation of several typical embodiments of the invention, may be had by referring to the drawing accompanying and forming a part of this specification wherein like reference characters designate the same or similar parts in the various views.

Fig. 1 is a part sectional elevation of a typical quadruple magnet electromagnetic pulley, the section having been taken along the irregular line l--i of Fig. 2;

Fig. 2 is a part sectional end view of the magnetic pulley shown in Fig. 1, the section having been taken along the line 22;

Fig. 3 is a side view of a magnetic separating installation embodying one of the improved electromagnetic pulleys cooperating with a troughed feed belt, and showing the installation in action;

Fig. c is a diagrammatic central longitudinal section through the upper half of a quadruple magnet pulley such as shown in Figs. 1 and 2, showing the relative disposition of the magnets and the magnetic field acting upon the layer of bulk material; and

Fig. 5 is a diagram similar to that of Fig. 4 but depicting a dual magnet pulley embodying a modification of the invention.

While the invention has been illustrated and described herein as being especially applicable to magnetic separating drums or pulleys cooperating with troughed feed belts, it is not the intent to unnecessarily restrict th invention to such installations; and it is also contemplated that specific descriptive terms employed herein be given the broadest possible interpretation consistent with the disclosure.

Referring to Figs. 1 to 4 inclusive of the drawing, the quadruple electrically energized magnetic pulley shown therein, comprises in general, a main shaft i having a series of four annular magnets 8 mounted thereon each of which is provided with a pair of poles 9, i separated by an annular space and which may have annular magnetic pole shoes l l secured thereto; an electric energizing coil or winding i2 confined within the annular space of each magnet 8; and a series of non-magnetic coil cover rings l3 interposed between the successive pole shoes II and cooperating with these shoes ii and with non-magnetic end rings slightly crowned or fiat annular pulley face.

The annular magnets 8 and their poles 9, iii are formed of magnetically permeable material and of similar construction, each being provided with a central hub i5 connected thereto by radial arms l6 and which are firmly secured to the shaft 1' by means of keys ll. The corresponding arms iii of all of the magnets 8 are united by tie-bolts is which clamp the adjoining poles 9, H} of the successive magnets snugly against each other. The annular pole shoes I 1 preferably extend laterally over the peripheries of the adjacent coils l2 and are also formed of magnetic material, being rigidly attached as by welding, to the peripheries of the adjacent annular poles 9, iii; and the nonmagnetic cover and end rings l3, Hi may also be rigidly secured to the adjacent magnet poles 9, l9 and pole shoes l I, in any suitable manner, as by welding.

The annular coils or magnet energizing wind- M to provide a ings l2 are surrounded by protective bands and are confined within the spaces between the magnet poles 9, ill; and these coils l2 are adapted to be energized from any suitable source of direct current through conductors passing through moisture proof cond ts 2!. These conduits 2i communicate with a central duct 22 formed in the shaft 1 through a sealed tubular coupling 23, and the energization of the windings [2 must be such as to cause all of the poles 9 to be of like as indicated by the letter N while the poles 10 must be of opposite polarity as indicated by the letter The improved magnetic pulley may be installed in a typical separating plant such as illustrated in Fig. 3, wherein the main shaft 1 is mounted in bearings 25 carried by inclined beams 25, and a non-magnetic conveyor belt 21 for bulk material 28 the major portion of which is composed of non-magnetic substance, but which may contain magnetic articles or substances 29, coacts with the periphery of the pulley. The material feeding belt 21 preferably has its upper inclined stretch 3G troughed in advance of the magnetic pulley by means of relatively inclined idler rolls 3! journalled on brackets 32 also carried by the beams 26 and a member 33 for segregating the removed magnetic substances 29 from the bulk material 28 is located beneath the magnetic pulley below the separating zone 36. The untreated bulk material may be deposited within the trough shaped upper belt stretch 38 from any suitable source, and the separating pulley may be continuously rotated in a clockwise direction as viewed in Fig. 3 either by the belt 21 or by power applied directly to the shaft 1, while the magnet windings 12 may be energized from any convenient source of direct current through conductors and a commutator in a well known manner, to create magnetic fields 35 as depicted in Fig. 4.

When the improved quadruple magnetic pulley has been properly constructed and assembled as described, and installed as illustrated in Fig. 3, the two flux fields 3'5 extending entirely around the pulley periphery will have greatest magnetic intensity at the center of the pulley and will also have considerable magnetic range between the pulley center and its opposite ends, because the adjoining positive poles 9 will concentrate the flux at the central pole shoe H, while the coacting positive and negative poles 9, 10 located between the pulley center and its opposite ends will neutralize each other. As the upper conveyor belt stretch 3B feeds the bulk material 28 toward the separating zone 3d, the trough shape thereof produced by the rolls 3! will permit the loose substance to be deposited in the form of a rather thick layer without having the material spill over the belt edges.

After leaving the rolls 3 l the upper belt stretch 38 flattens out and causes the upwardly advancing stream of material 28 to assume greater thickness along its mid-portion and to taper ofi toward its opposite sides as shown in Fig. 4, and when the layer of material passes through the separating zone 35 directly above the magnetic pulley the magnetic substances 2% will be attracted toward the pulley axis and will cling to the advancing belt 2! while the non-magnetic substance 28 will cascade and drop by gravity beyond the segregating member 33. As the lower run of the belt 21 advances downwardly away from the pulley periphery, it gradually pulls the magnetic substances 29 out of the fields of magnetic influence whereupon these substances drop by gravity beyong the left inclined side of the member 33.

stream of material, most efficient extraction and removal of the magnetic substances possible.

While the quadruple magnetic pulley of Figs. 1 to 4 inclusive has proven current electric winding l2 and having opposite poles 9, I 0 cooperating with H, are provided, but the gaps between the sucpecially from centrally thickened layers of the bulk substance.

From the foregoing detailed description it Will be apparent that the present invention provides poles 9, I 0 always of opposite polarity. In both of the improved magnetic pulleys shown, the adpolarity, while the poles ID at the opposite ends of the pulley have negative polarity, thus producing magnetic fields of considerable range and of maximum intensity at the thickest central porof bulk material 28.

center of the stream.

In the prior magnetic herein described, the magnetic lines of force reove terial r the conveyor belt 30, and that the bulk mamay be fed upon riphery without the use of a conveyor belt, in a l2 are energized.

It should be understood that it is not desired to limit th' References Cited UNITED STATES PATENTS Number Number in the file of this patent Name Date Buchanan Jan. 18, 1921 Buchanan Jan. 18, 1921 Ullrich Jan. 26, 1932 FOREIGN PATENTS Country Date Great Britain Feb. 8, 1899 

